We validate estimates of shallow sedimentary porosities made on the continental shelf by
electromagnetic methods through a comparison with those measured directly in cores.
Specifically, we show that an electromagnetic surveying system we have used to measure
sediment
resistivity in a number of seafloor locations returns porosity depth profiles
that are related to those measured in cores, and that our data have good sensitivity to the
structure within the upper-most few tens of centimeters of seafloor.
We then consider
inferences of sediment type made by observations of acoustic backscatter in the light of
our porosity measurements.
Our results suggest that electromagnetic methods provide complimentary information that can
be used to improve grain type estimates at and just below the seafloor, especially when combined with
acoustic backscatter data.
Because the system is pulled along the seafloor, data can be quickly collected from a
large area of seafloor and can be used to interpolate facies conditions
between core locations.